Elevator control system



June 1, 1937. E M B TON ET AL v 2,081,980

ELEVATOR CONTROL SYSTEM Filed July 11, 1.936 2 Sheets'Sheet 2 Era/FeHedda/7 00 L4 /2 19/9/1 Ma/or- AawjaeedMo/ar poor and L 60?": ari/a4 5L+ V V E6 L- WIINESSES: I INVENTORS' ATT NEY Patented June 1, 1937UNITED STATES PATENT OFFICE cago, 111., assignors to WestinghouseElectric Elevator Company, Chicago, 111., a corporation of IllinoisApplication July 11,

16 Claims.

Our invention relates to elevator control systems and more particularlyto systems for controlling the operation of the elevator motors inmaking one floor runs and in making runs of more than one floor as wellas effecting landings at the floors.

In the operation of elevator systems in which the cars are run atvarious speeds and particularly in two-speed systems in which the carsmay be operated at a normal low speed or a normal high speed, it isdifficult to provide an automatic control system which willautomatically decelerate the car from its high speed to a stop at afloor when the car has been making a run of more than one floor, and toalso cause the same car, in making a one floor run, to accelerate to itshighest speed for a one fioor run and then automatically decelerate tothe stop at the next floor. It is not practical to make a one floor runon low speed because too much time would be consumed in making the run.On the other hand, it is not practical, in a one floor run, to get thecar up to its highest speed, because the car could not reach such highspeed and yet be decelerated at an agreeable rate of deceleration tostop at the next floor. That is, the car cannot be accelerated to itsnormal high speed and then be decelerated to its landing speed withinthe confines of a one floor run.

Therefore, the object of our invention is to provide a system in which aone floor run may be automatically accomplished in the shortest possibletime consistent with agreeable acceleration and agreeable deceleration.

It is also an object of the invention to provide an elevator controlsystem which will automatil cally select and follow through theacceleration and deceleration necessary for a one floor run,

or the acceleration and deceleration for a run of -4 more than onefloor, without requiring any attention to such operation by the carattendant;

that is, to provide a system in which the car attendant will throw hisswitch for starting and stopping the car and will thereby automaticallycause the car to operate under the best running conditions whether therun is for one floor or for several floors.

It is also an object of our invention to provide an automaticdecelerating and stopping system for elevators in which the car may beinched into an accurate landing position at a floor if for some reasonthe automatic landing system causes the car to stop either a few inches55 short of or a few inches beyond the exact point 1936, Serial No.90,095

at which it should stop to take on or let off passengers.

For a better understanding of our invention, reference may be had to theaccompanying drawings, in which Figure 1 is a representation of anelevator car disposed for operation past several floors in a hatchway(not shown).

Fig. 2 is a diagrammatic representation of a control system foroperating the car shown in Fig. l, and

Fig. 2A is a diagrammatic representation of the relays embodied in thecontrol system shown in Fig. 2.

The diagram shown in Fig. 2 is drawn in what is known as the straightline style for electric circuits. The illustration of the relays in Fig.2A shows them with their coils and contact members disposed inhorizontal alinement with their positicns in the straight line circuitsof Fig. 2 so that the reader may readily determine the identity of anyrelay, the number and kind of its contact members and the position ofits coil and its contact members in the straight line circuit.

Referring more particularly to the drawings, we have illustrated anelevator car A disposed for operation past the 8th, 9th and 10th floorsin an elevator shaft indicated by the dotted line 1. Ohviously, the carmay serve any desired number of fioors and it may be suspended by asuitable cable I l which passes over an operating drum I2 to acounterweight 23.

The drum l2 for operating the car is driven by a low-speed motor It anda high-speed motor l5. The motors are mounted on a suitable shaft itconnected to the elevator drum l2 through a suitable reducing gear drivell so that the motors may operate at somewhat higher speed than thespeed at which it is necessary to drive the car. A suitableelectromagnetic brake I8 is provided for stopping the car and holding itin position when the motors are deenergized.

The low-speed motor M comprises a rotor 20 and a stator 2!, while thehigh-speed motor l5 comprises a rotor 22 and a stator 23. The stators ofthe motors are provided with impedance means shown as a plurality ofresistors TI to M2 to assist in controlling the acceleration anddeceleration action of the motors.

The motors may be connected to any suitable source of supply representedby the conductors Ll, L2 and L3, through a main line switch 24.

The control system for the motors is shown as supplied with low-voltageenergy from a pair of supply conductors L+ and L-, connected to the mainsupply circuit through a plurality of rectifiers 25. The rectifiers maybe of any satisfactory design, but preferably of the copper oxide type.

The relays, etc. in the system are listed i'ollows:

U=Up direction switch.

D=Down direction switch.

E=Low speed switch.

F=Low speed accelerating relay.

G=Low speed accelerating relay.

M=Time relay for low speed accelerating relay F.

N=Time relay for low speed accelerating relay G.

P=High speed relay.

Q Interlocking relay for high speed.

R=High speed switch.

S=High speed accelerating relay.

T=High speed accelerating relay.

V=Inductor energizing relay.

W=Slow down inductor relay.

X=Stopping inductor relay.

Y=Relay for selecting deceleration point or plate.

CS=Control switch in car.

The motors may be controlled to start and stop the car through the useof a manually operated switch or controller CS mounted in the car. Thecar switch is provided with two accelerating points, (a low-speed and ahigh-speed) for the up direction and two accelerating points, (alowspeed and a high-speed) for the down direction. In starting the car,the switch CS controls an up direction switch U and a down directionswitch D which prepare the motor circuits for connec tion to the mainline conductors Ll, L2 and L3. When the up direction switch U isenergized, the motors are prepared for operating the car in the updirection. When the down direction switch D is energized, the motors areprepared for operating the car in the down direction.

In addition to the direction switches, a lowspeed switch E, controlledby either the up direc tion switch U or the down direction switch D isprovided for connecting the low speed motor M for operation.

A first low-speed accelerating relay F and a second low-speedaccelerating relay G- are provided for controlling the connection of theresistors T1 to TIZ in the circuit of the stator 2| of the motor I.

A first time delay relay M and a second time delay relay N are providedfor controlling the low-speed accelerating relays F and G.

A high-speed relay P is provided for effecting control of the motors tooperate the car at high speed. This high-speed relay is responsive tomovements to the second or high speed points on the car switch and ithas associated with it a selfholding interlocking relay Q to insureacceleration and deceleration of the motors in correct order.

A high-speed switch R is disposed to be controlled by the high-speedrelay P for connecting and disconnecting the high-speed motor IE to thesupply conductors Ll, L2 and L3. Associated with the high-speed switchR, is a pair of highspeed accelerating relays S and T for connecting anddisconnecting the accelerating resistors TI to T6 in the circuit of the.stator of the motor IS. The relays S and T are provided with dash potsto delay their closing for predetermined periods so as to ensure theconnection and disconnection of the resistors aiter the expiration ofthe correct time intervals.

The circuit of the brake is includes contact members operated by the lowspeed switch E and the high speed switch R so that the brake will bereleased when either motor is energized to move the car. In accordancewith our invention, we have provided a novel arrangement for securing abetter operation of the control system than heretofore provided. Thisarrangement includes not only means for delaying the operation of thetime relays M and N but also a means for so connecting the interlockingrelay with the time relays M and N that will control the timing of theserelays to effect a rapid disconnection and connection of the resistorsr? to 112 with the 10W speed motor when the car is being inched into afloor and to eifect a slow disconnection of these resistors with the lowspeed motor when the car is being decelerated from a high speed run.

The car may be started in operation by moving the car switch to theright or left in accordance with the dir ction desired, and it may bestopped by centering the car switch; that is, by returning the switch toits off position. Any suitable landing system may be employed forautomatically stopping the car level with the floors it serves inresponse to the centering of the car switch. As one example of such alanding system, we have illustrated an automatic inductor relay landingsystem similar to that disclosed in Patent 1,864,42l6, issued Dctcber25, 1932, to K. M. White and G. H. l-liearn, and to the Westing houseElectric Elevator Company. This landing system responds to the centeringof the car switch by automatically decelerating and stopping the caraccurately level with the floor at the next floor landing. The lanchngsystem inchides high-speed decelerating device or inductor relay W and astopping inductor relay X for causing the car to be automaticallydecelerated from its high speed and brought to a stop at the floor atwhich it is to be stopped. The inductor relay W is mounted on the car inposition to cooperate with a decelerating device or inductor plate QDW'Lor QDWS for the down direction at the 9th floor. The stopping inductorrelay X cooperates with an inductor plate QDX for the down direction atthe 9th floor. The inductor plates are constructed of magnetic materialand are mounted in the hatchway in such position as to cooperate withand open the contact members of the inductor relays on the car when therelays are in an energized condition as the car approaches a stop at alanding.

For simplicity only the down inductor plates at the 8th and 9th floorsare shown in 1, but it will be understood that a similar set of downplates and a similar set of up plates may be provided for each floorserved by the car intermediate its upper terminal landing and its lowerterminal landing (not shown). The car may be stopped at its terminals bythe usual limit switches LS. down inductor plates at the 9th floor aremarked as plates SDWL and BDWS for deceleration and plate QDX forstopping.

As shown, each inductor relay is provided with two sets of contactmembers. For a down stop at the 9th floor, the contact members DWI ofrelay W cooperate with either the inductor plate QD'WL or the plate QDWSin starting deceleration to landing speed and the down contact membersQDX! oi the stopping relay X cooperate with the down stopping plate QDXin stopping the car after it is decelerated to its landing speed. Thisdeceleration and stopping is effected because the contact membersof theinductor relays are so connected with the car control circuits that,when the inductor relays are energized as the car passes the plates, theopening of the contact members eifects the deceleration and stopping ofthe car. For the up direction, the contact members UWI of relay W andthe contact members UK! of the relay X cooperate with up inductor plates(not shown) similar to those for the down direction.

The inductor relays are of the self-holding type, that is, when they areenergized but have not yet come opposite an inductor plate, the contactmembers remain closed, but when the relay comes opposite an inductorplate, the contact members adjacent that plate move to their openposition and are held in such open position until the inductor relay isdeenergized. However, if desirable, any other suitable type of inductorrelays may be utilized.

The exact position of the inductor plates in the hatchway and of theinductor relays on the cars cannot be here given because such positionsvary in each installation by reason of difference in hoisting motors,weight of cars, height of ceilings, etc. However, elevator mechanicshave found little diificulty in installing the plates and inductorrelays correctly when the cars are first tried out in operation, so thatthe car will be stopped level with the next floor to which it can beagreeably decelerated and stopped after centering of the car switch.

The elevator system illustrated in connection with this invention is ofthe type often utilized for operating cars at a speed of from 200 to 250feet per minute. In operating cars of this oharacter having a normal lowspeed motor and a normal high speed motor, we provide, in accord ancewith our invention, for automatically starting deceleration at onedistance ahead of the floor stop after a run of two or more floors andfor starting deceleration at a shorter distance from the floor stop inmaking only a one-floor run. In making a one-floor run, this permits thecar to be accelerated to the highest speed from which it can beagreeably decelerated and stopped at the next floor.

To carry out these features of the invention, the two deceleratingplates for each direction at each floor are positioned to startdeceleration at different points and a selecting relay Y is provided toautomatically so respond to the operation of the car control system soas to cause the decelerating inductor relay to be operated by the firstplate SDWL when stopping after a long run and by the plate SDWS whenstopping in a onefloor run. The high speed inductor plate QDWL for the9th floor is disposed to initiate deceleration of the car for a downstop at the 9th floor when landing from a run of two or more floors. Thehigh speed decelerating plate QDWS is mounted at a shorter distance fromthe 9th floor, so that a down car can accelerate from a stop at the thfloor to the highest speed from which it can be safely decelerated andstopped at the 9th floor and can then be safely decelerated by the plateSDWS to landing speed for the 9th floor.

It is believed that the invention may be understood best by an assumedoperation.

It will be assumed that the car A is standing above the 10th floor, say,at the 12th or 13th floor, and that the main line switch 24 is closed toprepare the car for operation. In this condition, the inductorenergizing relay V is energized but does not affect the system, as thecar is standing still. The car will be operated to run down to and stopat the 9th floor, thereby making more than a one-floor run. In startingthe car the attendant moves the car switch in its counter-clockwisedirection to full-on or high speed position for the down direction. Asthe switch engages its low speed position or first contact point 3t, itenergizes the down direction switch, to effect down operation of the carby the circuit: from L+ through CS-BU, LS2, D, 3|, to L-.

The energized switch D closes its contact members DI and D2, therebypreparing a down circuit for the motors M and I5 and closes its contactmembers D5, thereby energizing the selecting relay Y, the time delayrelay M, the time delay relay N and the low speed switch E for startingthe motor M and controlling its acceleration to its normal speed.

The circuit for relay Y extends from L+ through D5, Q2, Y, 33 to L. Thecircuit for relay M extends from L+ through D5, E4, M, 33, to L. Thecircuit for relay N extends from L+ through D5, F3, N, 33 to L. Thecircuit for relay E extends from L+ through D5, E, R6, 33 to L.

The closing of the contact members E3 of relay.-

E energizes the brake coil [8 by a circuit from. Li, through 24a, D2,E3, l8, Di, 24b to L2 to release the brake from the shaft 16. Theclosing of the contact members El and E2 of relay E completes thecircuit for the motor M to start it in operation. This motor circuitextends from Ll through 24a, D2, Zia, 1'1, rlfl to center junction 40;from L2 through 24b, DI, E2, Zlb, r8, rll to 4!]; from L3 through 240,El, 21c, T9, M2 to 40. The release of the brake and the energization ofthe motor I4 causes the car to be started on its down trip.

The opening of the contact members E4 of the relay E deenergizes therelay M but that relay does not open yet because of its time delayresistor H4.

Referring again to the operation of the car switch, the fact that it wasmoved immediately to its full-on or high-speed position at the startcaused the high speed motor to be energized right away after theenergization of the motor M. In fact, the energization of the motor l5and the deenergization of the motor [4 follow so closely that theresistors in the circuit of the motor M are not short circuited toexclude them before the motor [4 is cut out of opera tion and the motorI5 is put into operation. This. is accomplished by the switch CS closingits contact members 32, thereby energizing the highspeed relay P toeffect the starting of the motor l5, the cutting out of the motor [4 andthe ac celeration of the motor (5 to its normal high speed. The circuitfor relay P extends from L+ through 08-32, LS4, P to L-.

The energized relay P closes its contact members P3, thereby energizingthe interlocking high speed relay Q by a circuit from L+ through D5,v Q,Y2, P3, 33' to L. The energized relay Q immediately opens its contactmembers Q2, thereby deenergizing the selecting relay Y. However, therelay Y is provided with a timing element or resistor H3 so that itremains in its operated po sition for a predetermined time, but,inasmuch as the car is now operating on a long run, the finai opening ofthe relay Y can not affect the operation of the car and when it is to bestopped it will start its deceleration for a stop from a long run.

The closing of the contact members Q3 and Q4 connects the resistors T|5and TI! in the time delay circuits of the relays M and N to control thedelay period of those relays when the car is being decelerated to astop, as will be described later.

The closing of the contact members P2 of the energized relay P energizesthe high speed switch R for stopping the low speed motor I4 and forputting the motor I5 into operation and accelerating it to its normalhigh speed. This circuit extends from L+ through 34, R, P2 to L-.

The closing of the contact members RI and R2 of the energized relay Rcompletes a circuit for energizing the windings 23 of the high-speedmotor I5 for the down direction, and it now opcrates to run the car inthe down direction. This motor circuit extends from LI through 24o, D2,23a, rI, r4, to junction M; from L2 through 24b, DI, R2, 23b, T2, T5 to4|; from L3 through 24c, RI, 230, r3, T6 to 4|.

The opening of the contact members R3 of relay R deenergizes the lowspeed relay E which closes its contact members E4 to again energizerelay M and prevent acceleration of motor I4 and opens its contactmembers El and E2, thereby deenergizing the motor I4 so that it ceasesto affect the operation of the car. Both the motor I4 and the motor I5will be in an energized condition momentarily when the relays operate tochange from the low speed motor to the high speed motor and this willtend to provide a smooth transition from low speed operation to highspeed operation of the car.

The closing of the contact members R1 of the relay R energizes the highspeed accelerating relay S by a circuit from L+ through 34, S, R'I, P2to L-. This relay is provided with a dashpot 36 for delaying its closingfor a predetermined time. After the expiration of that predeterminedtime, the relay S closes, thereby closing its contact members SI and S2,thus short-circuiting the resistors r4, 15 and TB from the field circuitof the motor I5. This increases the torque oi the motor which results inincreasing its speed. As the same time, the operating relay S closes itscontact members S3, thereby energizing the high speed accelerating relayT. This relay T is also provided with a dashpot 3l' which prevents itfrom closing for a predetermined time after it is energized. Upon theexpiration of this predetermined time, the relay T closes its contactmembers TI and T2, thereby short-circuiting the resistors r1, 1'2 and r3in the field of the motor I5, thus increasing the torque of the motorwhich results in still further increasing its speed. The motor I5 nowmoves the car downwardly at normal high speed.

It will be assumed now that the car is moving down the shaft and that,as it passes the 9th floor, the attendant centers the car switch CS fora stop at the 8th floor. The centering oi the car switch will cause thecar to automatically decelerate and stop level with the 8th floor, byenergizing the inductor energizing relay V. The circuit for relay Vextends from L+ through CS-42, V to L-.

The energized relay V closes its contact members VI thereby energizingthe high speed inductor relay W by a circuit extending from L+ throughD5, VI, YI, W, 33 to L-. The relay W is energized immediately by theaction of the relay V because it is a long run and the contact membersYI have been closed by the timing out of the selecting relay Y.Therefore, the relay W will be operated by the long run plate BDWLinstead of the one-floor run plate BDWS. As the car continuesdownwardly, the energized relay W comes opposite the long run inductorplate BDWL and is thereby operated to open its contact members DWI. Theopening of the contact members DWI deenergizes the high speed relay P toeffect deceleration of the car from its normal high speed to its landingspeed. The deenergized relay P closes its contact members PI therebyenergizing the low speed switch E by the circuit previously described.The switch E closes its contact members EI and E2 thereby re-energizingthe windings 2| of the low speed motor I4 to start that motor inoperation, in the transfer of the car from operating by the high speedmotor to operation by the low speed motor.

The opening of the contact members E5 in the circuit of the high speedswitch R deenergizes that switch thereby causing it to open its contactmembers RI and R2 thus deenergizing the windings 23 of the high speedmotor I5. This cutting out of the motor I5 and cutting in of the motorI4 causes the car to decelerate.

The energized low speed switch E also opens its contact members E4thereby deenergizing the time relay M. After the expiration of apredetermined period, the deenergized relay M closes its contact membersMI thereby energizing the low speed accelerating relay F by a circuitfrom L+ through D5, MI, F, E6, 33 to L-. The energized relay F closesits contact members FI and F2 thereby short circuiting the resistorsrIll, TH, and H2 in a winding 2I of the motor I4, thus increasing theretarding torque of the motor.

It should be noted that the time delay in the deenergizing of the relayM in this particular instance is increased by reason of the fact thatthe contact members Q3 are closed in the circuit of the resistor rI5.This provides a parallel path through the resistor TM and rI5 therebygiving a lower resistance and increasing the time delay of the relay M.

The energized relay F also opens its contact members F3 in the circuitof the energized relay N. By reason of the fact that the relay N isprovided with time delay resistors TIE and TI! and the fact that thecontact members Q4 in the circuit of the resistor RI'I are closed, thetime delay of the relay N is also increased. The relay N is fullydeenergized and closes its contact members NI thereby energizing theaccelerating relay G by a circuit from L+ through D5, NI, G, E6, 33 toL. The energized relay G closes its contact members GI and G2 therebyshort circuiting the resistors r1, T8, and T9 in the motor I4, thusfurther increasing the retarding torque of the motor. The increasedtorque of the low speed motor efiects a further deceleration of the carfrom the high speed at which it was operated by the high speed motoruntil it comes down to its normal landing speed.

The closing of the contact members R5 energizes the stopping inductorrelay X to effect the stopping of the car when it gets to the 8th floor.This circuit extends from L+ through D5, VI, YI, R5, X, 33 to L-. As thecar, now operating at landing speed, approaches closely to the 8thfloor, the energized inductor relay X comes opposite the stoppinginductor plate 8DX and is energized thereby operated to open its contactmembers DXl to efiect the stopping of the car level with the floor. I'heopening of the contact members DXI in the circuit of the down directionswitch D, deenergizes that switch to stop the car level with the 8thfloor. The opening of the contact members Di and D2 deenergizes themotor i l. The opening of the contact members D deenergizes the lowspeed switch E which opens its contact members E3 thereby deenergizingthe brake l8 and applying it to stop and hold the car at the 8th floor.The opening of the contactmembers D5 also deenergizes the interloclo inghigh speed relay Q, the high speed inductor relay W and the stoppinginductor relay X.

By reason of the foregoing operation of the car over a long run, it isseen how it responds to the movement of the car switch in acceleratingto high speed,'how the decelerating inductor relay is energized beforethe car reaches the long run inductor plate by the centering of the carswitch, how the high speed motor is cut out and the low speed motor cutin in decelerating the car, how the resistors in the winding of the lowspeed motor [4 are brought in slowly by the time delay relays M and N tostill further decelerate the car and how the car is finally stoppedlevel with the 8th floor.

It will be assumed now that the car has been operated for some time andis at present standing at the 9th floor on a down trip. It will also beassumed that the car attendant, knowing that the car is to be stopped atthe 8th floor, moves the car switch in its counterclockwise direction tofull on position and then recenters it to make a one floor run and stopat the 8th floor. This operation will show how the selecting relay Yoperates to cause the decelerating relay W to fail to operate on thelong run plate BDW'L and to operate on the short run plate BDWS, whenmaking a one floor run.

The movement or the car switch to its full on position energizes thedown direction relay D and the high speed relay P to energize the timerelay M, the time relay N, the selecting relay Y, the slow speed switchE, the interlocking relay Q and the high speed switch R to acceleratethe car toward its high speed as described in connection with the longrun previously indicated. However, inasmuch as the car switch CS hasbeen re-centered, the inductor energizing relay V has been energized aspreviously described. This closes the contact members Vi in the circuitfor the high speed inductor relay W. However, the selecting relay Y,although it has been deenergized by the opening of the contact membersQ2, has not yet been deenergized, because of the time delay caused byits resistor rig. Therefore, its contact members Yl ar still open, andalthough the relay V has been energized, it cannot yet energize therelay W because of these open contact members. However, selecting relayY times out within a few seconds and then its con tact members Yl close.By this time, the car, upon leaving the 9th floor, has passed the longrun decelerating inductor plate SDWL. The closing of the contact members"ill of the relay Y and the already closed contact members Vi energizethe inductor relay W after the car passes the plate BDWL but before itreaches the plate BDWS, As the car continues toward the 8th floor, itpasses the inductor plate BDWS and the inductor relay W is therebyactuated to open its contact members DWl thus deenergizing the highspeed relay P to efiect deceleration of the car.

With the correct predetermined delay period for selecting relay Y andthe position of the in ductor plate BDWS, deceleration of the motor I5is started by the deenergization of the high speed relay P, before thetime delay relay T has had time to short circuit the resistors r1, T2and T3 in the high speed motor l5. Therefore, although the car hasreached a high speed, it has not quite reached the highest speed ofwhich it is capable. However, in making a one-floor run, the highestspeed of which the car is capable is not desirable because that wouldrequire an uncomfortably deceleration in order to stop at the nextfloor. Therefore, the relays are arranged to enable the car to reach thehighest speed from which it can, in making a one-floor run, he agreeblydecelerated to a stop at the next floor. The deenergization oi the highspeed relay P effects the energiaation of the low speed switch E, thedeenergization of the relays R, S and T, the energization of thestopping inductor relay X and the energization of the acceleratingrelays F and G to decelerate the car to its normal landing speed, in thesame manner as previously described in connection with the decelerationfrom the long run. Thus we have the same rate of deceleration as we hadfrom the long run even though the car did not get up to as high a speedon its short run as it did on its long run.

In view of the assumed long run operation and the assumed one-floor runoperation, it will be seen how the selecting relay Y operates, by reasonof its deenergization soon after the car starts and its predeterminedtime delay, to automatically select and control the point at whichdeceleration begins in stopping from a long run stop and in stoppingfrom a one-floor run, without any attention on the part of the carattendant beyond the necessity of centering his car switch within theproper time and that the car will, as a result thereof, automaticallydecelerate and stop level with the next floor.

Occasionally, it will be found that the car, for some reason, may failto stop exactly level with the floor. In such cases, it is desirable forthe car attendant to be able to inch the car either up or down into itscorrect position. In practicing our invention, we have provided forsecuring a more rapid response of the low speed motor is while it isbeing operated in an inching operation than it had in the usualaccelerating and decelerating operation. This is effected by causing thepredetermined periods of delay in the reclosing of the acceleratingrelays M and N to be long when the car is operating on a long run or aone-floor run and to be short when the car is responding to an inchingoperation. In the foregoing assumed operations, it was shown how thetime delay accelerating relays M and N were held open for apredetermined long period after being deenergized, by the effect of theclosed contact members Q3 and Q l of the interlocking relay Q, duringthe normal runs of the car. The following assumed operation is now givento show how the contact members Q3 and Q4 remain open during an "inchingoperation and thereby so afiect the time relays M and N as to cause themto time out in a short period instead of a long period.

It will be assumed now that the car failed to land exactly level withthe 8th floor and that, in fact, it landed a few inches above the 8thfloor. Under these circumstances, the car attendant desires to inch thecar down to the 8th floor and, therefore, moves the car switch OS fromits center position to its first down notch 30. Inasmuch as the switchCS is not moved to the notch 32 in this inching operation, the highspeed relay is not operated and consequently the high speed interlockingrelay Q is not energized. Therefore, the contact members Q3 and Q4 areopen to shorten the time delay of the accelerating relays M and N.However, the movement of the switch to the contact member 30 energizesthe down direction switch D, by the circuit previously described, toeffect movement of the car.

The energized switch D energizes the time delay relays M and N and thelow speed switch E, as previously described in connection with theoperations of the car already given.

The energized low speed switch E energizes the low speed motor l4 andthe brake ill. The release of the brake and the closing of the contactmembers El and E2 starts the motor in operation and the car movesdownwardly.

At the same time, the energization of the switch E opens its contactmembers E4 thereby deenergizing the time delay relay M. After theexpiration of a predetermined short period, the relay M drops outthereby closing its contact members Mi and energizing the low speedaccelerating relay F by the circuit previously described. The energizedrelay F closes its contact members Fl and F2 thereby short circuitingthe resistors H0, TH and M2 in the circuit of the low speed motor i4thus increasing its torque which causes it to accelerate rapidly.

The energized relay F also opens its contact members F3 therebydeenergizing the time delay relay N, which closes its contact members Niafter the expiration of a predetermined short period and therebyenergizes the second low speed accelerating relay G, which closes itscontact members GI and G2 thereby short circuiting the resistors T1, T8and T9 in the winding of the motor I. The elimination of these resistorsincreases the torque of the motor 14 which results in increasing itsspeed. As the car starts to inch toward the 8th floor, the car attendantcenters the car switch thereby opening its contact members 30 anddeenergizing the down direction switch D and consequently the low speedswitch E, the motor M, the brake I8 and the accelerating relays F and G,which again stops the car, this time level with the 8th floor.

In this connection, it should be noted that inasmuch as the interlockingrelay Q was not energized during the "inching operation, the con tactmembers Q3 and Q4 in the circuits of the resistors H5 and TI! were open,and, therefore, the time delay circuits for the relay M included onlythe resistor H4, and the time delay circuit for the relay N includedonly the resistor r16. This increased the resistance in the time delaycircuits of these relays and thereby caused them to cut out much quickerthan when the car was accelerating or decelerating with the high speedlocking relay energized while they were making a one or more floor run.It will be apparent that this quick action of the accelerating relays isof benefit in inching into a level position with the floor because itcauses the low speed motor to pick up quickly right at its start.However, it will also be apparent that such a quick action on the partof accelerating relays when changing from the high speed motor to thelow speed motor would not prove satisfactory and that it is much better,when decelerating from high speed, to cause the accelerating relays tooperate slowly so as to give the passengers an agreeable rate ofdeceleration. Hence, it is seen that our novel provision of theinterlocking relay Q and the time delay relays having different periodsof timing out controlled by the relay Q have a decided advantage inoperation.

It will also be seen that we have provided an elevator system in whichthe deceleration and acceleration in long run, one-floor run and inchingoperations is automatically controlled by the elevator system itselfwithout the necessity of special attention or special operation of anyde* vices by the attendant on the car.

Although we have illustrated and described only one specific embodimentof our invention, we desire it to be understood that many changestherein and many modifications thereof may be made without departingfrom the spirit and scope of the invention.

We claim as our invention:

1. In an elevatorsystem :foroperating a carserving a plurality offloors, means for causing the car to start from a floor, means forcausing the car to decelerate and stop at a floor, and a time delaydevice responsive to operation of the start ing means for preventingoperation of the decelerating means for a predetermined time afteroperation of the starting means.

2. In an elevator system for operating a car serving a plurality offloors, a car switch, means responsive to operation of the car switch toits high speed position for causing the car to operate at a high speed,means responsive to movement of the car switch to its off position fordecelerating and stopping the car at the next floor landing, and aselective device for controlling deceleration of the car to begin at onepredetermined distance from the landing at which it is to be stoppedwhen the car makes a onefloor run and for controlling the decelerationof the car to begin at another predetermined distance from the landingat which it is to be stopped when the car makes a run of more than onefloor.

3. In an elevator system for operating a car serving a plurality offloors, a control system comprising a car switch, a high speed relayresponsive to operation of the car switch for causing the car to operateat a high speed, means for causing deceleration and stopping of the carat a floor, means responsive to operation of the car switch and tooperation of the high speed relay for preventing operation of thedecelerating means for a predetermined period after operation of thehigh speed relay.

4. In an elevator system for operating a car serving a plurality offloors, a controller means responsive to operation of the controller toan on position for starting the car in operation, means responsive tooperation of the car switch to its off position for decelerating andstopping the car at the next floor for which it can be decelerated andstopped, a high speed relay responsive to operation of the controller toits high speed position for causing the car to operate at high speed, aselective device responsive to operation of the car switch to an onposition in starting the car, and means responsive to operation of thehigh speed relay for causing the selective device to delay the operationof the decelerating means for a predetermined period of time.

5. In an elevator system for operating a car serving a. plurality offloors, a car switch, means responsive to operation of the car switch inits on direction for starting and operating the car, means responsive tomoving the car switch to its 0 position for decelerating and stoppingthe car at the next floor for which it can be decelerated and stopped, aselective device connected for operation by operation of the car switchto an on position, a high speed relay responsive to operation of the carswitch to its high speed on position for causing the car to operate atits high speed, a self-holding interlocking relay connected foroperation by operation of the high speed relay, means responsive tooperation of the interlocking relay for returning the selective deviceto its normal condition, means associated with the selective device fordelaying for a predetermined time its return to normal condition, andmeans responsive to the return of the selective device to its normalcondition for rendering the decelerating means responsive to the nextoperation of the car switch to its off position.

6. In an elevator system for operating a car serving a plurality offloors, a car switch, a high speed relay responsive to operation of thecar switch to its high speed position for causing the car to operate athigh speed, means responsive to operation of the car switch from itshigh speed position to its oif position for decelerating the car, saiddecelerating means comprising an inductor relay on the car and along-run decelerating plate and a short-run decelerating plateassociated with each floor for cooperation with the inductor relay indecelerating the car for that floor, the long-run plate being disposedfarther away from the floor than the short-run plate, a selective deviceconnected for operation by operation of the car switch to an onposition, an interlocking relay connected for operation in response tooperation of the high-speed relay, means responsive to operation of theinterlocking relay for returning the selective device to its normalcondition, means associated with the selective device for delaying for apre determined time its return to normal condition, and means responsiveto the return of the selective device to its normal condition forrendering the inductor relay responsive to the operation of the carswitch to its off position, whereby the inductor relay will be renderedeffective for cooperation only with the long-run plate for the nextfloor to decelerate the car from a morethan-one-floor run and can berendered eifective to cooperate only with the short-run plate for thenext floor when making only a one-floor.

'7. In an elevator system for operating a car serving a plurality offloors in a hatchway, control means, means responsive to operation ofthe control means for causing the car to run at high speed, means fordecelerating the car, said decelerating means including a deceleratingdevice on the car and a long-run cooperating device and a short-runcooperating device associated with each floor in the hatchway, and meansresponsive to a car-stopping operation of the control means in making amore-than-one-floor run for causing the decelerating device to beoperated by the long-run cooperating device for the floor at which astop is to be made to decelerate the car and responsive to acar-stopping operation of the control means in making a one-floor runfor preventing operation of the decelerating device by a long-runcooperating device and causing it to be operated by the short-runcooperating device for the floor at which the stop is to be made todecelerate the car, whereby deceleration of the car will be started inaccordance with a long or a short run.

8. In an elevator system for operating a car serving a plurality offloors in a hatchway, control means, means responsive to one operationof the control means for causing the car to run at high speed, means fordecelerating the car, said decelerating means including an inductorrelay on the car and a cooperating long-run plate and a cooperatingshort-run plate associated with each floor in the hatchway, andaselective device responsive to operation of the control means in makinga morethan-one-floor run for causing the inductor relay to be operatedto decelerate the car only by the long-run plate for the floor at whichthe stop is to be made and responsive to operation of the control meansin making a one-floor for preventing operation of the inductor relay bya long-run plate and causing it to be operated to decelerate the car bythe short-run plate for the floor at which the stop is to be made,whereby deceleration of the car will be started in accordance with along or a short run.

9. In a power system, an electric motive means, control means foreffecting the starting and stopping of the motive means, meansresponsive to operation of the control means for varying the torque ofthe motive means, and means responsive to predetermined degrees ofoperation of the control means for varying the rate at which the torqueof the motive means is varied.

10. In a pow-er system, a low speed electric motor and a high speedelectric motor for operating a device, a control means for starting andstopping the motors, means responsive to a predetermined operation ofthe control means for the on direction for energizing the 10w speedmotor, means responsive to a continued operation of the control meansfor said on direction for deenergizing the low speed, motor andenergizing the high speed motor, means responsive to operation of thecontrol means for varying the torque of the motors, and means responsive to the degree of operation of the control means for varying therate at which the torque varying means effect variation in the torque ofthe low speed motor.

11. In an elevator system for operating a car serving a plurality offloors, a low speed motor and a high speed motor for operating the car,a controller for controlling the energization of the motors, impedancemeans connected With the low speed motor for varying its torque, meansresponsive to a predetermined operation of the controller for varyingthe amount of impedance at one rate, and means responsive to anotherpredetermined operation of the con troller for controlling the impedancevarying means for operation at another rate.

12, In an elevator system for operating a car serving a plurality offloors, a low speed motor and a high speed motor for operating. the car,a controller for controlling the energization of the motors, a pluralityof resistors disposed in and a high speed motor for operating the car, acontroller, for controlling the operation of the motors, meansresponsive to operation of the controller from its 01f position to itsslow speed position for starting and to movement from said low speedposition to said off position for stopping the slow speed motor,impedance for controlling the torque of said slow speed motor, meansresponsive to operation of the controller from said off position to saidlow speed position for varying the amount of said impedance for the slowspeed motor after the expiration of a predetermined time, meansresponsive to operation of the controller from said low speed positionto its high speed position for deenergizing said slow speed motor, forenergizing said high speed motor, and for changing the impedance varyingmeans to vary the amount of said impedance after the expiration of adifferent predetermined time when the slow speed motor is againenergized.

14. In an elevator system for operating a car serving a plurality offloors, a low speed motor and a high speed motor for operating the car,a controller for controlling the energization of the motors, meansresponsive to operation of the controller from its ofi to its low speedposition for energizing the low speed motor, and return of thecontroller to its off position Without advancing beyond said low speedposition for deenergizing the low speed motor, means responsive tooperation of the controller from said low speed position to its highspeed position for deenergizing the slow speed motor and energizing thehigh speed motor, means responsive to operation of the controller fromsaid high speed position to its oil" position While the car is inoperation for successively effecting deenergization of the high speedmotor, reenergization of the low speed motor and subsequentdeenergization of the low speed motor to stop the car, impedance meansassociated with the low speed motor, a time relay responsive tooperation of the controller to its low speed position for controllingsaid impedance to vary the torque of the low speed motor, means fordelaying operation of the time relay for a predetermined time, and meansresponsive to operation of the con troller to its high speed positionfor causing the delaying means to delay operation of the time relay fora greater predetermined time than said first predetermined time when theslow speed motor is being energized during deceleration of the car fromhigh speed.

15. In an elevator system for operating a car serving a plurality offloors, a low speed motor and a high speed motor for operating the car,a controller for controlling the energization of the motors, meansresponsive to operation of the controller from its ofi to its low speedposition for energizing the low speed motor and to return of thecontroller to its off position Without advancing beyond said low speedposition for deenergizing the low speed motor, means responsive tooperation of the controller from said low speed position to its highspeed position for deenergizing the low speed motor and energizing thehigh speed motor, means responsive to operation of the controller fromsaid high speed position to its off position While the car is inoperation for successively effecting deenergization of the high speedmotor, reenergization of the low speed motor and subsequentdeenergization of the low speed motor to stop the car, impedance meansassociated with the low speed motor, a first accelerating relay and asecond accelerating relay for controlling the impedance, a time relayresponsive to operation of the con troller to its low speed position forcontrolling the first accelerating relay for varying a portion of theimpedance to vary the torque of the low speed motor, a second time relayresponsive to operation of said first accelerating relay for controllingsaid second relay for varying another portion of the impedance toadditionally vary the torque of the low speed motor, means for delay theoperation of each of the time relays for a predetermined time, meansresponsive to operation of the controller to its high speed position forcausing each of the delaying means to delay operation of its time relayfor a greater predetermined time than said first predetermined time whenthe low speed motor is being energized during deceleration of the carfrom high speed.

16. In an elevator system for operating a car serving a plurality offloors, a low speed motor and a high speed motor, a controller, meansresponsive to operation of the controller to its low speed position forenergizing the low speed motor, means responsive to operation of thecontroller to its off position for deenergizing the low speed motor tostop the car, means responsive to operation or" the controller to itshigh speed position for causing the high speed motor to operate the' carat high speed, means responsive to operation of the controller from itshigh speed position to its low speed position for decelerating andstopping the car at the next floor, a selective device responsive tooperation of the controller from its on? position to its low speedposition, means responsive to operation of the controller to its highspeed position for causing the selective device to prevent operation ofthe decelerating means for a predetermined time after the con troller isoperated to its high speed position, impedance means connected with thelow speed motor for varying its torque, means responsive to operation ofthe controller to its low speed position for varying the impedance atone rate, and means responsive to operation of the controller to itshigh speed position for controlling the impedance varying means tooperate at a rate different from said first named rate when the lowspeed motor is next energized in deceleration the car from high speed.

EDGAR M. BOUTON. HAROLD W. WILLIAMS.

